This AS3340 VCO build has everything you can possibly need from a classic analog VCO (imho). I used a verified stripboard layout and the electrosmith submodule: Link
3340 VCO – electrosmith submodule build
This AS3340 VCO build has everything you can possibly need from a classic analog VCO (imho). I used a verified stripboard layout and the electrosmith submodule: Link
knopsl modular 